IONIC MOBILITY AND PHASE TRANSITION IN HEPTAFLUORODIANTIMONATE(III) Cs0.4Rb0.6Sb2F7
V. Ya. Kavun1, M. M. Polyantsev1, L. A. Zemnukhova1,2
1Institute of Chemistry, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia
2Far Eastern Federal University, Vladivostok, Russia
Keywords: гептафтородиантимонаты(III) цезия, рубидия, ионная подвижность, фазовый переход, ионная проводимость, спектры ЯМР 19F, ДСК, cesium-rubidium heptafluorodiantimonates(III), ionic mobility, phase transition, ionic conductivity, 19F NMR spectra, DSC
Abstract
The ionic mobility and conductivity in the crystalline phase of Cs0.4Rb0.6Sb2F7 (I) is studied using 19F NMR, DSC, and impedance spectroscopy methods. The analysis of the 19F NMR spectra makes it possible to follow the character of ion motions in the fluoride sublattice in the temperature range of 150−470 K, and to determine the types and temperature ranges of these motions. It is found that diffusion of fluorine ions becomes the dominant type of ion motions in the modification formed as a result of the reversible phase transition ( T = 415 K, the DSC data) in compound I. According to the preliminary results of electrophysical studies, the ionic conductivity in this compound is ~10-3 S/cm at temperatures above 450 K.
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